#include <bits/stdc++.h>
using namespace std;
using uint=unsigned int;
using ll=long long;
using ull=unsigned long long;
using i128=__int128;
const int N=1e6+5;

string multyply()(string a,int b){
    if(b==0)return "0";
    vector<int> res;
    int carry=0;
    //从地位到高位处理a的每一位
    for(int i=a.size()-1;i>=0;i--){
        int num=a[i]-'0';
        int product=num*b+carry;
        res.push_back(product%10);
        carry=product/10;
    }
    //处理剩余进位
    while(carry){
        res.push_back(carry%10);
        carry/=10;
    }
    //构造结果字符串
    string ans;
    for(int i=res.size()-1;i>=0;i--){
        ans+=to_string(res[i]);
    }

    return ans;
}